Annular Tear or Fissure

What is an annular tear or fissure?

An annular tear or fissure is a crack in the outer part of the spinal disc called annulus fibrosus.

Is an annular tear the same as a herniated disc?

An annular tear means only a crack in the outer part of the disc. Later, a part of the soft disc center may or may not squeeze (herniate) through the crack [7].

An annular tear without a herniation is also called internal disc disruption [10].

What causes an annual tear?

An annual tear usually develops slowly as part of the aging process or degenerative disc disease, but it can also occur after an injury [2,5].

What are symptoms of an annular tear?

An Annular Tear of a Lumbar Disc (L4-L5 or L5-S1)

An annular tear of a lumbar disc without a herniation causes either no pain or pain in the middle of the lower back (without leg pain), which is known as discogenic lumbar pain[13,14,15,17].

An annular tear with inflammation or a herniation that results in a pinched nerve root (radix) results in radicular lumbar pain. One example of such pain is known as sciatica, which appears in the buttock, back of the thigh and calf, or foot, usually only on one side [4,17].

The pain can be aggravated by sitting, bending, lifting, coughing or exhaling through a closed nose (Valsalva maneuver) [6,14].

In summary: An annular tear without inflammation or a herniation usually causes pain limited to the middle lower back, but in a tear with inflammation or a herniation, the pain can also radiate down the leg.

An Annular Tear of a Cervical Disc (C4-C5 or C5-C6)

An annular tear of a cervical disc without a herniation causes either no pain or pain at the back of the neck and along the middle border of the shoulder blade on the affected side [11].

An annular tear with a herniation and a pinched nerve root can cause pain, tingling or numbness in the shoulder and outer side of an arm, forearm and hand, usually only on one side [11].

How is an annular fissure diagnosed?

The first investigation for an unexplained neck or lower back pain is usually an X-ray but this cannot show annular tears [15].

The next investigation for a pain that is suspected to arise from a spinal disc, is a magnetic resonance imaging (MRI), but this does not reveal all annular fissures [1,6]. An MRI with gadolinium (a contrast substance injected into a vein) can show more details [7,16].

Picture 1. An MRI showing an annular tear (a short vertical gray line near the red arrow) in a disc in the lumbar spine (source: Degruyter.com, CC license)

A CT discography, which includes an injection of a contrast substance into a disc followed by a CT, better shows annular fissures than an MRI [1,7]. The pain during the test that is similar to your existing back or neck pain suggests that the pain arises from the disc [7,8]. Discography is not considered a very reliable investigation and may worsen the pain [14].

What do the annular fissure grades mean?

Grading of annual fissures on magnetic resonance images is used to evaluate their severity [7]:

Grade 0: No visible fissure

Grade 1: A fissure extends across less than 1/3 of the thickness of the annulus fibrosus

Grade 2: A fissure extends across more than 1/3 of the thickness of the annulus fibrosus, but there is no gross disc deformity

Grade 3: A fissure extends through the entire thickness of the annulus fibrosus and is associated with an obvious disc bulge, protrusion or herniation.

What are a central (posterior) and paracentral annular fissure?

A central or posterior annular fissure is located in the middle of the back side of the disc and a paracentral tear is located slightly to the right or left [2].

What is a concentric annular fissure?

A concentric annular fissure is parallel to the disc circumference; it is rarely seen in an MR image [2].

What is a radial annular fissure?

A radial annular fissure runs from the disc border toward the disc center [2]. Posterior (central) annular fissures are almost always a sign of a severe degenerative disc disease [5,7].

What is a peripheral annular fissure?

A peripheral annular fissure is a crack underneath the disc surface and close to the vertebra; it is usually caused by an injury [2,5,7].

How is an annular tear treated and what is its healing time?

Annular tears may not heal at all or heal over several months with scars [5,7,15].

The pain from an annular tear can resolve on its own with relative rest in several weeks or months [6,7,11].

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, may relieve the pain [6,7].

Surgery is not the first treatment option for annular tears. Surgical treatment may relieve pain when [3,4,6]:

Fardon DF et al, 2014, Lumbar disc nomenclature: version 2.0: Recommendations of the combined task forces of the North American Spine Society, the American Society of Spine Radiology and the American Society of Neuroradiology The Spine Journal